Ok so I fixed the leak. Now it misfires! :( :(

Well, actually it started misfiring yesterday, before I fixed the leak today.

Been laning for a few days, fine.

120 mile drive home, fine.

Took it for a jetwash, fine.

Drove it to town to pick something up, not fine.

Started this morning, moved it about, fine.

Once it warmed up, and I had fixed the coolant leak, it started missing.

You could blame the jetwash but believe me this car gets caked in **** and washed off again on a weekly basis so its not like it's a rare thing to jetwash the motor.

I've also had misfires before, this doesn't seem quite like what I've had before. Most times it misses on tickover, and really struggles to rev up.

This is more of a hesitation/stumble when you blip the throttle, but then it's not bad to drive and it's pretty happy to rev up to the redline.

I was thinking perhaps it's an injection misfire? Ignition is very precise, this is more of a half miss, i think. It just seems softer, not as acute. Not sure.

Anyway, checked coolant temp sensor, that's doing what it should. With the engine ticking over, unplug the sensor and it idles up, as expected. It seems to rev up better, less lumpy with the sensor disconnected. Plug it back in and it goes very lumpy again, not so much lumpy tickover but struggles to blip.

The fuel temp sensor however makes no difference plugged or unplugged. I couldn't find any data on fuel temp resistances, but mine seems to read around 1900 ohms cool and 1100 ohms working temp.

Any ideas please folks?

Im only asking this Q cos I don't think its ignition, seems different.

Interestingly as I left the garage before it drove great but when it got warmed up it went lumpy, although it still drove down the road quite reasonably. Drop a gear and give it a blip and it's all stuttery.

Hmmm, please help all ye experienced ones

I just learnt that the fuel temp sensor and coolant temp sensor read the same values, so that means the coolant was about 80 odd degrees and the fuel was around 30 degrees which seems good to me.

So. Odd.

Will check the ignition timing tomorrow just to be sure!

Sounds like t could be fuel related, maybe pressure regulator? Try disconnecting the vaccum hose to it and see if it improves.

Saying that if its temp related could be your ignition amp or coil breaking down under the temp. That could affect fuel injection timing as the neg pulse from the dizzy to the coil sends a signal back to the ecu to tell it when to inject.

Actually could be anything, AFM, throttle pot...

Have you plugged in a code reader yet Sam?

vac advance?
play/knackered dizzy rotor? (I had one where the metal contact had lifted and was loose in its plastic housing assembly, causing similar symptoms)
Loose ignition module plug (on the side of the dizzy)
A sticking fuel injector? (also had exactly this occur with the last engine in the bobtail before I did a better job and killed the engine for good)...
or dodgy electric plug contact on one of the injectors?
A load of crap in the primary throttle main jet if these babies were running on webbers...unfortunately not tho

Good luck

Cheers guys

Went for a fairly long evaluation drive yesterday.

Only seems to start missing when up to full temp, but it's the weirdest thing. It'll be off on a few cylinders, then you can floor it and it'll quite easily drive through it and pull to 5k without missing, then drop to tickover at the lights and be fine, but lumpy of you blip it up. But then a moment later it would be sweet. Then you set off and it'll be ok, or it'll go off on like 3 cylinders, and won't tickover.

Seems to come and go all the time!

I've actually made my own ignition amp loom because the old wires failed, so that's just a pair of spade connectors onto it. I'll check them and make sure cos it does seem like that sort of issue.

However it could easily be an injection problem, I really can't decide. It was popping a fair bit more than normal yesterday, I 'think' it may have even backfired on overrun yesterday. There was a loud bang and I don't think it was an exhaust pop, could have been. What's a backfire suggesting?

And no I haven't got a code reader joe

Thanks guys!

dare I say it....the coolant isn't over pressurising is it?!...
No, course not...sorry, I shall wash m mouth out with soapy water!

...sounds more like MAF or a lazy injector or bad injector connection t me.
If ya wanna borrow my EFi probe to check injectors are opening n closing as they should, you're most welcome if ya can make it up to north Manchester today?

code reader is a good idea, but conecting it up can (and mostly) is a pain for the first time as some (ie most) ECU's haven't got the correct connection for my ebay code reader....first time I used it I had to do a bit of soldering (the female connection came with it but is still soldered to m off roader)

Hi joe.

NO of course the coolant isn't over pressure you dirty animal!!

Urm yeah thanks very much for the offer, shame I didn't get back on the forum earlier cos I coulda come over

I havent got any diagnostic wiring in my ECU so would have to wire up into the ECU plug aswell.

Perhaps I'd bring the car over to you and we could have a look?

Anyway I'll check all my connections/resistances over etc first and see how it goes.

Cheers

No probs Sam...
As it happens I went out on a quick test drive. A work mates nextdoor neighbour got 101 Forward Control off his dad for xmas, so I was just going over to have a look at it...friggin 'ell he's got a project and a half!......
I went out on a test drive too as I just replaced a front wheel bearing on the bobtail, great stuff...only for another noise to start grinding like a bitch just as I turned in to home about 15mins ago......a rear bearing has decided to wave bye bye now too...DAMMIT.....enthusiastic driving over off road crap, with 30mm spacers seems to be eating through bearings and brake pads at a rate of knots. bearings seem to be an annual service item and pads get chewed through within 6months!!! LOL....good job the parts are cheap as chips, and easy to diagnose compared to engine issues!

Yeah, you're welcome anytime. I can't promise myricals, but I can scratch m head and suck air thro m teeth like the best of 'em!! lol

It really does sound like a loose electrical connection, ignition module or if not the MAF or an injector. It's a pain having to run through the possibles...have had a fair share myself so know what its like

p.s...if its coil related you're in luck...I seem to have accumulated them somehow...got about 5 or 6 for some reason!! dou

Alright cheers joe

Pads dont last if you're offroad, I find the grit gets thrOugh the
Very quickly.

Bearings for me are alright though and I'm on negative offset wheels. When I first renewed all four I was retightening every few weeks but theyve been fine now for over a year. Do you pack the complete hub with grease? I find this helps.

Will be in touch!

Mr Noisy said:

Alright cheers joe

Pads dont last if you're offroad, I find the grit gets thrOugh the
Very quickly.

Bearings for me are alright though and I'm on negative offset wheels. When I first renewed all four I was retightening every few weeks but theyve been fine now for over a year. Do you pack the complete hub with grease? I find this helps.

Will be in touch!

Click to expand...

Yep, defo pack properly, and palm full of grease to load up the bearing before install & there's defo a knack to bending those lock washers 'just so'.....the front one I've just done was a right royal pain in the arse to be honest as the stub axle could have done with being replaced really, but an extra washer saw m use a different part of the thread that hadn't gone flat suspect with previuos owners going gorilla at trying to take the slack out of knackered bearing sets!:doh:
I've had more success with bearings when I've actually taken m time to clean things up and get rid of the mud n grit before the new ones go in...I guess its defo one of those jobs where cleanliness counts
(I recon some pay n play sites are sitting on some excellent material ideal for use as a grinding paste)

Yeah, if ya need a second pair of eyes any time, send me a pm...I'm only just off J19 of M60 (not far from Heaton Park), so not a mssive distance from ya

Top man joe, if you're on 10 spline axles I could bring you a spare stub axle for your time!

Mr Noisy said:

Top man joe, if you're on 10 spline axles I could bring you a spare stub axle for your time!

Click to expand...

I certainly am on 10....Brill...In fact you're welcome to do a swap with a 24 spline /metric hub I bought by mistake a while back...assuming you're on the later (better lube design) 24s ?

Don't think any of my RRC run 24s unfortunately

No mate, 10 spline all the way for me. Don't want any of your 24 spline tosh thanks!

I prefer 10 spline hub design, keeps things old skool!

Mr Noisy said:

No mate, 10 spline all the way for me. Don't want any of your 24 spline tosh thanks!

I prefer 10 spline hub design, keeps things old skool!

Click to expand...

LOL good man!
but seriously, if you have a stub axle spare with a good thread it would be much appreciated, especially if it also still has the bronze bearing (the split dimpled type)
I'll even pay ya for it.........pm me

Yep I've got some of them.

Pm sent.

Mr Noisy said:

Yep I've got some of them.

Pm sent.

Click to expand...

cheers

to lazy to read all the posts mate , but when I had that it was the tps but it did show up on the faultcode reader if you have one. I changed everything else first though :doh:

Fett, just to clarify, you had a stumbley/stuttery misfire when warmed up and it was the tps?

I will check that, cheers!

fett said:

to lazy to read all the posts mate , but when I had that it was the tps but it did show up on the faultcode reader if you have one. I changed everything else first though :doh:

Click to expand...

Are you sure Fett?!
Does the Telephone Preference Service sort out V8's as well as unwanted telesales